1. Field of the Invention
This invention relates to a disc driving apparatus, and more particularly to a disc driving apparatus that is adapted to drive a disc accommodated in a cartridge stabbly.
2. Description of the Prior Art
Generally, a disc, particularly a rewritable disc, having a high density is very sensitive to a contaminant such as dust, finger print, etc., and a physical damage such as scratch or the like. Accordingly, in order to protect the surface of the disc from the contaminant and the physical damage, the disc is usually accommodated in a cartridge made from plastic material, etc.
The disc cartridge is provided with an opening for exposing a part of information recording face. This opening is opened and closed by means of a shutter engaged thereto. The shutter is opened by a shutter opener when the cartridge is introduced to the disc driving apparatus, thereby rotating the disc in such a manner that a part thereof is exposed. Due to this, a non-symmetrical air flow is created around the rotating axis of the disc at the cartridge in which the disc is rotated. A pressure difference occurs within the cartridge because of the non-symmetrical air flow, so that the disc rotated within the cartridge vibrated constantly in a certain period. Particularly, a rotation speed of the disc is faster and a thickness of the disc is thinner, such a disc vibration appears more seriously.
As described above, the disc vibration occurring upon rotation of the disc within the cartridge unstabilizes an information recording and reproducing operation of the disc driving apparatus, so that it causes a problem of depreciating a responsibility of information. Also, when the disc vibration becomes serious, a recording face of the disc collides with the inner surface of the cartridge, so that a fatal problem of suffering a physical damage such as scratch and so on in the recording face occurs. In order to solve these problems, strategies for minimizing the disc vibration has been studied.
Accordingly, it is an object of the present invention to provide a disc driving apparatus that is capable of driving a disc within a cartridge stably, to assure a responsibility of recorded and reproduced information.
In order to achieve the above and other objects of the invention, according to an aspect of the present invention, there is provided with a disc driving apparatus wherein a vertical position of the disc is set in such a manner that a force by a difference in an air pressure within the cartridge is generated in the same direction as a force clamping the disc during rotation of the disc.
According to another aspect of the present invention, there is provided with a disc driving apparatus comprising supporting means for supporting the disc at a level higher than a supporting surface of the cartridge by a predetermined height in such a manner that the disc is positioned above the half height of the cartridge.
According to still another aspect of the present invention, there is provided with a disc driving apparatus comprising supporting means for supporting the cartridge at a level lower than a supporting surface of the disc by a predetermined height in such a manner that the disc is positioned above the half height of the cartridge.
According to still another aspect of the present invention, there is provided with a disc driving apparatus wherein the disc is rotated in a state in which the disc is positioned above the half height of the cartridge.
According to still another aspect of the present invention, there is provided with a disc driving apparatus including means for accommodating the disc; and driving means for rotating the disc, wherein a position relationship between the accommodating means and the driving means is set in such a manner that the disc is positioned above the half height of the accommodating means.